﻿using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;

namespace CandooMwrf
{

    /// <summary>
    /// byte[]与16进制互转
    /// </summary>
    public static class ByteHexHelper
    {
        private static char[] _buffedChars = null;
        private static byte[] _buffedBytes = null;

        static ByteHexHelper()
        {
            _buffedChars = new char[(byte.MaxValue - byte.MinValue + 1) * 2];
            int idx = 0;
            byte b = byte.MinValue;
            while (true)
            {
                string hexs = b.ToString("X2");
                _buffedChars[idx++] = hexs[0];
                _buffedChars[idx++] = hexs[1];

                if (b == byte.MaxValue) break;
                ++b;
            }

            _buffedBytes = new byte[0x67];
            idx = _buffedBytes.Length;
            while (--idx >= 0)
            {
                if ((0x30 <= idx) && (idx <= 0x39))
                {
                    _buffedBytes[idx] = (byte)(idx - 0x30);
                }
                else
                {
                    if ((0x61 <= idx) && (idx <= 0x66))
                    {
                        _buffedBytes[idx] = (byte)((idx - 0x61) + 10);
                        continue;
                    }
                    if ((0x41 <= idx) && (idx <= 70))
                    {
                        _buffedBytes[idx] = (byte)((idx - 0x41) + 10);
                    }
                }
            }
        }

        /// <summary>
        /// 字节数组转16进制字符串
        /// </summary>
        /// <param name="bytes"></param>
        /// <returns></returns>
        public static string ByteToHex(byte[] bytes)
        {
            if (bytes == null)
            {
                return null;
            }

            char[] result = new char[bytes.Length * 2];
            for (int i = 0; i < bytes.Length; ++i)
            {
                int startIndex = (bytes[i] - byte.MinValue) * 2;
                result[i * 2] = _buffedChars[startIndex];
                result[i * 2 + 1] = _buffedChars[startIndex + 1];
            }

            return new string(result);
        }

        /// <summary>
        /// 16进制字符串转字节数组
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static byte[] HexToByte(string str)
        {
            if (str == null || (str.Length & 1) == 1)
            {
                return null;
            }

            byte[] result = new byte[str.Length / 2];
            int charIndex = 0;
            int byteIndex = 0;
            int length = result.Length;
            while (--length >= 0)
            {
                int first = 0;
                int second = 0;
                try
                {
                    first = _buffedBytes[str[charIndex++]];
                    second = _buffedBytes[str[charIndex++]];
                }
                catch
                {
                    return null;
                }
                result[byteIndex++] = (byte)((first << 4) + second);
            }
            return result;
        }

        #region CRC校验
        /// <summary>
        /// CRC高位校验码checkCRCHigh
        /// </summary>
        static byte[] ArrayCRCHigh =
        {
        0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
        0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
        0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
        0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
        0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
        0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
        0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
        0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
        0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
        0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40,
        0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
        0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
        0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
        0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40,
        0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
        0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
        0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
        0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
        0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
        0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
        0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
        0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40,
        0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
        0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
        0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
        0x80, 0x41, 0x00, 0xC1, 0x81, 0x40
        };

        /// <summary>
        /// CRC地位校验码checkCRCLow
        /// </summary>
        static byte[] checkCRCLow =
        {
        0x00, 0xC0, 0xC1, 0x01, 0xC3, 0x03, 0x02, 0xC2, 0xC6, 0x06,
        0x07, 0xC7, 0x05, 0xC5, 0xC4, 0x04, 0xCC, 0x0C, 0x0D, 0xCD,
        0x0F, 0xCF, 0xCE, 0x0E, 0x0A, 0xCA, 0xCB, 0x0B, 0xC9, 0x09,
        0x08, 0xC8, 0xD8, 0x18, 0x19, 0xD9, 0x1B, 0xDB, 0xDA, 0x1A,
        0x1E, 0xDE, 0xDF, 0x1F, 0xDD, 0x1D, 0x1C, 0xDC, 0x14, 0xD4,
        0xD5, 0x15, 0xD7, 0x17, 0x16, 0xD6, 0xD2, 0x12, 0x13, 0xD3,
        0x11, 0xD1, 0xD0, 0x10, 0xF0, 0x30, 0x31, 0xF1, 0x33, 0xF3,
        0xF2, 0x32, 0x36, 0xF6, 0xF7, 0x37, 0xF5, 0x35, 0x34, 0xF4,
        0x3C, 0xFC, 0xFD, 0x3D, 0xFF, 0x3F, 0x3E, 0xFE, 0xFA, 0x3A,
        0x3B, 0xFB, 0x39, 0xF9, 0xF8, 0x38, 0x28, 0xE8, 0xE9, 0x29,
        0xEB, 0x2B, 0x2A, 0xEA, 0xEE, 0x2E, 0x2F, 0xEF, 0x2D, 0xED,
        0xEC, 0x2C, 0xE4, 0x24, 0x25, 0xE5, 0x27, 0xE7, 0xE6, 0x26,
        0x22, 0xE2, 0xE3, 0x23, 0xE1, 0x21, 0x20, 0xE0, 0xA0, 0x60,
        0x61, 0xA1, 0x63, 0xA3, 0xA2, 0x62, 0x66, 0xA6, 0xA7, 0x67,
        0xA5, 0x65, 0x64, 0xA4, 0x6C, 0xAC, 0xAD, 0x6D, 0xAF, 0x6F,
        0x6E, 0xAE, 0xAA, 0x6A, 0x6B, 0xAB, 0x69, 0xA9, 0xA8, 0x68,
        0x78, 0xB8, 0xB9, 0x79, 0xBB, 0x7B, 0x7A, 0xBA, 0xBE, 0x7E,
        0x7F, 0xBF, 0x7D, 0xBD, 0xBC, 0x7C, 0xB4, 0x74, 0x75, 0xB5,
        0x77, 0xB7, 0xB6, 0x76, 0x72, 0xB2, 0xB3, 0x73, 0xB1, 0x71,
        0x70, 0xB0, 0x50, 0x90, 0x91, 0x51, 0x93, 0x53, 0x52, 0x92,
        0x96, 0x56, 0x57, 0x97, 0x55, 0x95, 0x94, 0x54, 0x9C, 0x5C,
        0x5D, 0x9D, 0x5F, 0x9F, 0x9E, 0x5E, 0x5A, 0x9A, 0x9B, 0x5B,
        0x99, 0x59, 0x58, 0x98, 0x88, 0x48, 0x49, 0x89, 0x4B, 0x8B,
        0x8A, 0x4A, 0x4E, 0x8E, 0x8F, 0x4F, 0x8D, 0x4D, 0x4C, 0x8C,
        0x44, 0x84, 0x85, 0x45, 0x87, 0x47, 0x46, 0x86, 0x82, 0x42,
        0x43, 0x83, 0x41, 0x81, 0x80, 0x40
        };
        /// <summary>
        /// CRC校验
        /// </summary>
        /// <param name="data">校验的字节数组</param>
        /// <param name="length">校验的数组长度</param>
        /// <returns>该字节数组的奇偶校验字节</returns>
        public static Int16 CRC16(byte[] data, int arrayLength)
        {
            byte CRCHigh = 0xFF;
            byte CRCLow = 0xFF;
            byte index;
            int i = 0;
            while (arrayLength-- > 0)
            {
                index = (System.Byte)(CRCHigh ^ data[i++]);
                CRCHigh = (System.Byte)(CRCLow ^ ArrayCRCHigh[index]);
                CRCLow = checkCRCLow[index];
            }

            return (Int16)(CRCHigh << 8 | CRCLow);
        }

        public static Int16 CRC16(byte[] data)
        {
            return CRC16(data, data.Length);
        }
        #endregion CRC校验

        public static byte[] Encrypt(byte[] inputByteArray, byte[] sKey)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            des.Key = sKey;
            des.IV = sKey;
            MemoryStream ms = new MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            cs.Close();
            return ms.ToArray();
        }
        public static byte[] Decrypt(byte[] inputByteArray, byte[] sKey)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            des.Key = sKey;
            des.IV = sKey;
            MemoryStream ms = new MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            cs.Close();
            return ms.ToArray();
        }

        public static byte[] DESEncrypt(byte[] data, byte[] sKey)
        {
            return DESEncrypt(data, sKey, sKey);
        }
        /// <summary>
        /// CBC-DES加密
        /// </summary>
        public static byte[] DESEncrypt(byte[] data, byte[] key, byte[] iv)
        {
            //注：已省略检查参数合法性等代码，以缩短帖子长度
            byte[] result = null;
            using (DES des = new DESCryptoServiceProvider() { Key = key, IV = iv })
            {
                des.Mode = CipherMode.ECB;
                des.Padding = PaddingMode.None;
                result = des.CreateEncryptor().TransformFinalBlock(data, 0, data.Length);
            }
            return result;
        }
        public static byte[] DESDecrypt(byte[] data, byte[] sKey)
        {
            return DESDecrypt(data, sKey, sKey);
        }
        /// <summary>
        /// CBC-DES解密
        /// </summary>
        public static byte[] DESDecrypt(byte[] data, byte[] key, byte[] iv)
        {
            byte[] result = null;
            using (DES des = new DESCryptoServiceProvider() { Key = key, IV = iv })
            {
                des.Mode = CipherMode.ECB;
                des.Padding = PaddingMode.None;
                result = des.CreateDecryptor().TransformFinalBlock(data, 0, data.Length);
            }
            return result;
        }
    }
}
